Propellant explosive



Patented May 17, 1932 UNETED rare FFEQE JOSEPH ID. IVICNUTT, OF NEWHAVEN, CONNECTICUT, ASSIGNOB, BY MESNE ASSIGN- MENTS, TO WIN CHESTERREPEATING- ARMS COMPANY, A CORPORATION OF MARY- LAND PROIELLANTEXPLOSIVE No Drawing.

My invention relates to an improvement in propellant explosive powders,the object being to produce a propellant powder of such a character thatsmall charges of it will burn uniformly and that it will leave nocorrosive residuum to act on the material of the barrel of the firearmin which it is used.

With these ends in view my invention comprises a propellant powderconsisting essentially of a nitrated organic compound, a heavy metalnitrate, sulphur, charcoal and basic lead nitrate. More specifically, myimproved propellant powder comprises gun cotton, barium nitrate,sulphur, charcoal and basic lead nitrate.

In carrying out my invention, I employ the above named ingredients insubstantially the following proportions, dependent on the specific useto be made of the compound: barium nitrate 51%, charcoal 9.5%, sulphur7.5%, basic lead nitrate 17% and gun cotton 15%.

It is well known to those skilled in the art that, in the case of smallcaliber rim fire cartridges wherein a small charge of propellant powderis used, it is difiicult to use the ordinary smokeless powders ofcommerce, owing to the fact that such powders will not burn uniformlyunder the conditions presented when used in such cartridges. On thisaccount and in order to produce cartridges of the type described, havinga high degree of accuracy when used, it has been customary in the pastto use various so-called semi-smokeless powders in such cartridges.These semi-smokeless powders comprise varying mixtures of gun cottonwith ordinary black powder. Black powder is a mixture whose chiefingredients are charcoal, sulphur and potassium nitrate.

It is well known that the oxide, hydroxide, and salts of the alkalimetals and in particular of potassium are highly hygroscopic. As aresult of this fact the residues from these semi-smokeless powdersdeposited in the Application filed July 26, 1929. Serial No. 381,389.

barrel of the firearm in which they are used have a highly corrosive orrust producing effect thereon, owing to the absorption by them ofmoisture from the air, dissociation therein and consequent efiect uponthe metal of the barrel.

In compounding the mixture the sulphur, charcoal, barium nitrate andbasic lead nitrate are first made into a compacted and granulatedmixture by the methods ordinarily used for the manufacture of blackpowder. The gun cotton used is very finely shredded gun cotton which hasnot been colloided in any way. It is mixed with black powder, made asabove described, in a mill with suflicient water to render the massplastic. When the mixture has been thoroughly incorporated, it is dried,grained, polished, sieved, etc. as is well known in the art.

I am aware that propellant powders have been made in the past in which asmall proportion of the potassium nitrate has been replaced by bariumnitrate, but none of these powders has been commercially successful, nordid any of them accomplish the result attained by my invention in whichthe compounds of alkali metals are entirely eliminated.

My invention is not restricted to the precise percentages shown above asthese are merely the preferred percentages for use in one specific smallcaliber rim fire cartridge and these proportions may be varied to meetthe individual requirements of other cartridges in which the ingredientsare to be used.

In place of gun cotton I may substitute another nitrated organicexplosive such as nitroglycerine, nitro-starch, nitro-sugar, etc. inwhich case the relative proportions of the ingredients will, of course,be altered to meet the conditions required.

I claim 1. A propellant powder, comprising a ni-

